1. Technical Field
The present disclosure relates to system software and more specifically to an operating system providing multi-touch support for (user) applications in a mobile device.
2. Related Art
A mobile device commonly refers to a hand held computing device. Mobile devices, being small, often contain touch/display screens which allow users to interact with the display using one or more fingers (used synonymously with stylus type pointing implements which provide similar touch function).
Multi-touch screens (having multi-touch capability) are designed to recognize and track several simultaneous touches. For example, when a user moves her fingers in two different areas on a screen, information indicating touch/movement for both fingers is provided by a multi-touch screen. In contrast, a single/standard touch screen (having single touch capability) may recognize and track only one touch corresponding to a single finger.
Applications are implemented in systems with touch screens to provide convenient user interface based on touches from the user. The touch based interfaces are designed to elicit user inputs (e.g., yes or no, a specific value, zoom factor/direction, etc.) required during execution of an application as is well known in the relevant arts.
Interface between the (user) applications and touch screens is commonly provided by an operating system/system application (typically by what are termed as device drivers in the relevant arts), which in general receives data representing a touch from the touch screen and forwards the corresponding information to the applications in a suitable format.
Operating system is often provided by one business entity and the hardware unit of the mobile device is assembled and provided by another business entity. The operating system may contain device drivers designed for interfacing with single touch screens only, for example, because a substantial number of the hardware units contain single touch screens. Examples of such operating systems are Windows CE5, Windows CE6, Windows Mobile 5 or Windows Mobile 6 operating systems, all available from Microsoft Corporation.
However, the same operating system may be required to be installed on hardware units with multi-touch screens, for example, due to contractual or other business reasons. In such a situation, applications may not receive indications of multiple touches, even if the applications are designed for responding to multiple touches, since the device drivers in the operating system are not designed for handling multiple touches.
An approach such as replacing a single touch driver with a multi-touch driver may not be feasible since an operating system (e.g., in the operating systems from Microsoft Corporation noted above) components themselves have binding to a single touch driver. Binding implies that the design of the operating system requires loading and execution of the single-touch driver when the mobile device is initialized (e.g., powered on) with the operating system.
An operating system provided according to an aspect of the present invention overcomes such a problem, while supporting multi-touch applications, as described in sections below.
In the drawings, like reference numbers generally indicate identical, functionally similar, and/or structurally similar elements. The drawing in which an element first appears is indicated by the leftmost digit(s) in the corresponding reference number.